PO installed mystery capacitor?

[Frank_Zappa]

Hi Guys. I have my aux. battery tray out for rust treatment and I found that the PO had installed what looks like a capacitor on the blue wire that comes out of the voltage regulator. Does anyone know why or what purpose it might serve and if I could remove it from the wiring harness without messing anything up? It is the object in the fingers of my left hand that has a connector showing that the blue wire has broken away from. Thanks. Oh yeah this is on my 1971 K20 P/U.

[swamp rat]

I have never known one to be in the system on a stock truck, I would say pull it but maybe it was installed for something my trucks never had?

heres a schematic

http://67-72chevytrucks.com/gallery/...&size=big&cat=

[Robznob11]

I don't know why but I'll give you a theory. On old vehicles that had points they used resistance. Wire in the system. When you switch to electronic you have to remove it so that the hei will have full voltage at crank. Maybe for some reason he was having a voltage drop to that wire ( not the hei I know that was just and example) and so he installed a cap to give him the voltage he needed at start up. Lol just an idea

[In The Ten Ring]

That's the capacitor for an EMP weapon. Those were popular in the late 70's to prevent police from both chasing and reporting speeders.

[FirstOwner69]

I'm no expert but...

At least the radio equipped trucks, but maybe all, came with condensers (often now referred to as capacitors) at the voltage regulator and distributor. I believe, but am not sure, their purpose was to reduce static on the radio.

However, they did not look like the one in the picture.

[truckster]

Maybe the PO was one of the Mothers of Invention...

[swamp rat]

But would the cap suppress ign noise to the radio if it is hooked to this blue wire which runs from the regulator to the alternator? i was led to believe the noise is from the distributor and plugs ect. I have had suppressors on the power wire to the radio, supresssion plug wires and resistor plugs but nothing on this wire. If so then i just learned something new.

[FirstOwner69]

Originally Posted by swamp rat

But would the cap suppress ign noise to the radio if it is hooked to this blue wire which runs from the regulator to the alternator? i was led to believe the noise is from the distributor and plugs ect. I have had suppressors on the power wire to the radio, supresssion plug wires and resistor plugs but nothing on this wire. If so then i just learned something new.

I think you are correct regarding the source of the noise, but these are the locations where GM put them. It's the same on my 58 Vette. The originals had a clip that went under one of the regulator screws and under one of the coil nuts (I believe the positive post). I'm not near those 2 vehicles to check wire colors, etc. Rock Auto has pictures of the correct replacements under the "ignition" listings.

EDIT: Here's a link to a thread with pics.
http://67-72chevytrucks.com/vboard/s...d.php?t=462189

Another tread... http://67-72chevytrucks.com/vboard/s...d.php?t=647732

[franken]

It looks like one side isn't connected to anything now, so it isn't doing anything.
I've seen them connected to the regulator in the past, but stock it would have a bracket and screw to the regulator mount. Most likely to reduce arcing on the contacts in the regulator when they open--same as the condenser in a points ignition.

[Frank_Zappa]

Originally Posted by truckster

Maybe the PO was one of the Mothers of Invention...

Hmmmmm Well the guy that I bought the truck from did resemble Jimmy Carl Black. Good answer. I remembered the thing about ignition noise but also felt that it was in the wrong place to suppress that. I think that I will reconnect the wire where it has broken and leave it in the system for now. Thanks for everyone's input.

[Davidf]

+1 on radio noise suppression. Easier/cleaner to install noise filter on radio power/ground lines.

[RichardJ]

Ya, sure.

The blue wire at your thumb nail is connected to the "F" terminal of the regulator. The bottom of the item you are holding looks to be a blue wire and would have been cut away from the other blue "F" wire. That blue wire would go to the Field winding "F" in the Alternator.
If that is a capacitor, it would block current to the Field and the alternator would not charge. I may be some king of choke coil. Trash it and reconnect the field wire.

[Fitz]

Originally Posted by Frank_Zappa

Hi Guys. I have my aux. battery tray out for rust treatment and I found that the PO had installed what looks like a capacitor on the blue wire that comes out of the voltage regulator. Does anyone know why or what purpose it might serve and if I could remove it from the wiring harness without messing anything up? It is the object in the fingers of my left hand that has a connector showing that the blue wire has broken away from. Thanks. Oh yeah this is on my 1971 K20 P/U.

On that side of the regulator it was probably put there to quiet static in the radio caused by a noisy alternator. It really doesn't do much so you can remove it without hurting anything.

[swamp rat]

Originally Posted by FirstOwner69

I think you are correct regarding the source of the noise, but these are the locations where GM put them. It's the same on my 58 Vette. The originals had a clip that went under one of the regulator screws and under one of the coil nuts (I believe the positive post). I'm not near those 2 vehicles to check wire colors, etc. Rock Auto has pictures of the correct replacements under the "ignition" listings.

EDIT: Here's a link to a thread with pics.
http://67-72chevytrucks.com/vboard/s...d.php?t=462189

Another tread... http://67-72chevytrucks.com/vboard/s...d.php?t=647732

Thanks for the explanation! I have not had an external regulator in my truck for some time now. Now next time i have the noise problem i'll have to dig a little deeper.